Method of using a pierce nut insertion tool

ABSTRACT

A pierce nut insertion tool is provided. In another aspect, a pierce nut feeding mechanism has a mechanically independent driver actuator from that of a punch. A further aspect of the present tool employs a member, moveable with a punch, that retains a pierce nut prior to fastening of the nut to a workpiece. An additional aspect uses a fluid actuated nut feeder including a piston.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a divisional application of U.S. patentapplication Ser. No. 13/308,583, filed on Dec. 1, 2011, which claimspriority to U.S. Provisional Patent Application Ser. No. 61/419,376,filed on Dec. 3, 2010, both of which are incorporated by referenceherein.

BACKGROUND AND SUMMARY

The present invention generally pertains to fastening machines and moreparticularly to a pierce nut insertion tool.

It is well known to install pierce nuts in sheet metal panels. Exemplaryinstallation machines are disclosed in the following U.S. Pat. No.3,108,368 entitled “Method of Sizing and Installing a Pierce Nut in aPanel” which issued to Steward on Oct. 29, 1963; U.S. Pat. No. 6,257,814entitled “Self-Attaching Fastener, Method of Forming Same and Method ofAttachment” which issued to Müller on Jul. 10, 2001; U.S. Pat. No.6,925,698 entitled “Method of Feeding and Installing Self-AttachingNuts” which issued to Goodsmith et al. on Aug. 9, 2005; and U.S. Pat.No. 6,957,483 entitled “Self-Diagnosing Pierce Nut InstallationApparatus” which issued to Woods on Oct. 25, 2005. All of these patentsare incorporated by reference herein. Various of these conventionalmachines, however, require complex cam-rotated fingers or spring loadedball bearings biased to engage a separated nut aligned with a ram priorto ram extension; these complex moving parts are subject to wear anddamage, are difficult to service, and are of heightened concern sincethey also contact against the high force ram. Furthermore, theseconventional machines do not allow for independent control and timing ofa nut feeding mechanism. Moreover, it can be a challenge to strip thenut from connective wires, and then orient and center the pierce nutrelative to the die throughout the ram and nut travel.

U.S. Pat. No. 5,172,467 entitled “Installation Apparatus for InstallingSelf-Attaching Fasteners” which issued to Muller on Dec. 22, 1992,discloses a pneumatically driven piston for shuttling a single stud.This patent is incorporated by reference herein. This apparatus,however, is overly simplistic and can only push a single stud from anintermediate supply tube per stroke, thereby incurring long cycle timesand misfeed concerns. The piston is externally mounted and requiresexpensive external valve control and connections by the user.

In accordance with the present invention, a pierce nut installation toolis provided. In another aspect, a pierce nut feeding mechanism has amechanically independent driver or actuator from that of a punch. Yetanother aspect provides a fluid actuated pierce nut feeder, morepreferably with an internal valve and/or control arrangement toadvantageously reduce installation complexity and increase cycle speed.A further aspect of the present tool employs a member, attached to apunch, that retains a pierce nut prior to fastening of the nut to aworkpiece. A serviceable pierce nut feeding mechanism is provided in yetanother aspect of the present tool.

The present tool is advantageous over conventional machines. Forexample, the independent actuator for the present pierce nut feedingmechanism allows the operator to change settings on a programmablecontroller in order to vary a stroke length or end distances, and alsoto vary the timing of the feed mechanism relative to a punch actuator.This can additionally be varied between different types of pierce nutsand workpiece configurations. In the internally valved and/or controlledconfiguration, external customer installation complexity is reducedwhile still allowing for the force and cycle speed benefits of fluidactuation; expensive sensors for the piston location are also notrequired with this approach. The present tool advantageously accuratelycenters and orients the pierce nut relative to the punch and die withminimal tool components. A manual feeding mechanism for the pierce nutis also employed in addition to an automatically powered actuator.Furthermore, the low profile body and nut feeding mechanism of thepresent tool is advantageously configured to place the pierce nut closerto edges and flanges of workpieces than many traditional machines. Thepresent tool provides more space between a bottom of a punch-side tooland the workpiece. Additional advantages and features of the presentinvention will be found in the following description and accompanyingclaims, as well as in the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a pierce nut insertion tool;

FIG. 2 is an exploded perspective view showing a punch-side of theinsertion tool;

FIG. 3 is a side elevation view showing the punch-side of the insertiontool;

FIG. 4 is an end elevation view showing the punch-side of the insertiontool;

FIG. 5 is a bottom elevation view showing the punch-side of theinsertion tool;

FIG. 6 is a top elevation view showing the punch-side of the insertiontool;

FIGS. 7 and 8 are cross-sectional views of the insertion tool;

FIG. 9 is a perspective view showing a plunger employed in the insertiontool;

FIG. 10 is a side elevation view showing the plunger employed in theinsertion tool;

FIG. 11 is an enlarged and fragmentary side view showing the plungerengaging a pierce nut, of the insertion tool;

FIG. 12 is similar to FIG. 11, but viewed 90° therefrom;

FIG. 13 is a side elevation view showing a die-side of the insertiontool;

FIG. 14 is a top and true elevation view showing the die-side of theinsertion tool;

FIG. 15 is similar to FIG. 13; but viewed 90° therefrom;

FIG. 16 is a perspective view showing the pierce nut positioned relativeto the die-side of the insertion tool;

FIG. 17 is a fragmentary, perspective view showing the die-side of theinsertion tool;

FIG. 18 is an enlarged and fragmentary side elevation view, in thedirection of arrow 18 in FIG. 17, showing a tapered edge of the die-sideof the insertion tool;

FIG. 19 is a fragmentary, perspective view showing a second embodimentof the die-side of the insertion tool;

FIG. 20 is a fragmentary, perspective view showing a third embodiment ofthe die-side of the insertion tool;

FIG. 21 is a side elevational view showing a preferred embodiment of apunch-side of a pierce nut insertion tool, in a closed and nut fasteningposition;

FIG. 22 is a cross-sectional view, taken along line 22-22 of FIG. 21,showing the preferred embodiment insertion tool, in a fully openposition;

FIG. 23 is a fragmentary and sectional view, taken along line 23-23 ofFIG. 22, showing the preferred embodiment insertion tool, in anintermediate position approximately 5.5 mm from the fully open position;

FIG. 24 is a side elevational view showing the preferred embodimentinsertion tool, in the fully open position;

FIG. 25 is a cross-sectional view, taken along line 25-25 of FIG. 24,showing the preferred embodiment insertion tool;

FIG. 26 is a side elevational view showing the preferred embodimentinsertion tool, in the intermediate position;

FIG. 27 is a cross-sectional view, taken along line 27-27 of FIG. 24,showing the preferred embodiment insertion tool, in the fully openposition;

FIG. 28 is a cross-sectional view, taken along line 28-28 of FIG. 21,showing the preferred embodiment insertion tool, in the closed position;and

FIG. 29 is a sectional view, taken along line 29-29 of FIG. 28, showingthe preferred embodiment insertion tool, in the closed position.

DETAILED DESCRIPTION

An alternate embodiment of a pierce nut insertion tool 31 is illustratedin FIG. 1-7. Tool 31 is used to clinch pierce nuts 33 to a sheet metalpanel or workpiece 35. Tool 31 includes a punch-side assembly 37 and adie 39, between which are loaded workpieces 35. A generally T-shapedbase 41 is secured to a moveable platten 43 of a press and die 39 issecured to a fixed platten 45 of the press, both by way of screws 47 anddowels 49. Multiples of tool 31 may be employed in the same press toinstall multiple pierce nuts in a simultaneous manner.

Pierce nuts 33 each have a generally rectangular top view periphery 51and an internally threaded central hole 53. A set of pierce nuts 33 areheld together in a linear string by a pair of frangible wires 55 securedwithin corresponding upper grooves in each pierce nut. Pierce nuts 33are fed into a generally L-shaped rack or body 57 which islongitudinally moveable relative to base 41.

Referring to FIGS. 2 and 7, base 41 includes a longitudinally elongatedbore 81 and a piston chamber 83. A punch assembly 85 is located in bore81. Punch assembly 85 includes a longitudinally elongated punch 87,fixed to base 41 by a roll pin 89, and a plunger 91, threadably securedwithin a hollow shaft of the punch. Furthermore, an automatically drivenpiston actuator 93 is moveably located within chamber 83. U-cup sealssurround piston, and an end cap 95 and end plate 97 are secured to base41 over the piston chamber. A pair of proximity sensors 99 are alsopositioned in piston chamber 83 to sense end of stroke positioning ofpiston 93; a connector and switch pack 100 provides electrical signalaccess to sensors 99. A piston rod 103 extends from piston 93. A pin 105connects an end of rod 103 to a central section of body 57.

Body 57 includes a guide block 121 and a nose plate 122. Guide block 121has a laterally elongated track or depressed channel within which piercenuts 33 are fed. Guide block 121 is screwed to a bottom (as viewed inFIG. 7) of the body. Body 57 further has a piston chamber 123. Anautomatically actuated piston 141 is laterally moveable within chamber123. A structure 143 extends from piston 141. Pistons 141 and 93 arepreferably pneumatically operated. An extension arm and knob 145externally project from an end of piston 141 to allow manual movement ofthe piston when it is deenergized. This allows for manual feeding of thepierce nuts during initial loading of a new string of nuts or forservicing of the tool. Piston seals, an end cap 147 and a proximitysensor 149 are also provided. Pistons 95 and 141 are mechanicallyindependent from each other so that they can be actuated at differenttimes depending on the type of nut being fed, sheet metal workpiececharacteristics, and the like. A pneumatic port 161 (see FIG. 4) causespiston 93 to advance and a port 163 causes piston 93 to retract.Similarly, a port 165 causes piston 141 to retract and a port 167 causespiston to advance, when pneumatic fluid flows therein as dictated by aprogrammable controller controlling pneumatic valves.

Pierce nut feeding is carried out by a feeder 171 which includes aknuckle 173, a pawl 175 and piston 141. Knuckle 173 rotates about apivot pin 177 coupled to an end of a structure 142 opposite piston 141.A compression spring 179 biases the adjacent section of knuckle 173 awayfrom structure 142. Pawl 175 includes a generally conical end with arounded tip, and a threaded opposite end. The threaded end of pawl 175is received within an internally threaded socket of knuckle 173. Thus,pawl 175 can be removed from knuckle 173 and replaced when worn duringnormal use and maintenance. An access plate 181 is removeably attachedto a side surface of body 57 to allow service access to pawl 175. Pivotpin 177 is attached to holes in a bifurcated end of structure 142associated with piston 141, and a head of pin 177 rides within anelongated slot 185 (see FIGS. 2 and 3) in body 57 to deter pistonrotation. Pin 177 is also accessible behind access plate 181.

Referring to FIGS. 5, 7 and 8, an elongated access slot 191 is locatedin a bottom of body 121. This provides visual and hand-tool (e.g., ascrewdriver) access to the string of pierce nuts 33 within body 121.This allows for manual feeding or removal of pierce nuts 33 when beinginitially inserted into the tool or for being removed during toolservicing. Moreover, a compression spring 193, ball bearing 195 andretaining bushing are provided within a bore in body 121; the ballbearing temporarily engages the center hole of each pierce nut 33 in adetent-like manner prior to severing of the nut from the string. Aretention plate 197 is screwed to body 121 to create an abutting servicefor spring 193 opposite ball bearing 195.

Feeder 171 acts as follows. Piston 141 is advanced from the position ofFIG. 8 to that of FIG. 7 in a lateral direction transverse to alongitudinal insertion axis 199 (see FIG. 3) which is coaxial with punchassembly 85. Simultaneous with this motion, spring 179 rotates knuckle173 which causes the conical end of pawl 175 to enter the center hole ofa nut 33 and then pushes the string of attached nuts forward toward axis199.

The nut feeding is performed while piston 93 is advanced and spaces body57 substantially away from base 41 as is shown in FIG. 8. Thereafter,piston 93 is reverse actuated so as to retract body 57 toward base 41(similar to the position of FIG. 7 but before the press advances thetool toward the die). This body movement causes a leading pierce nut 33to engage around externally threaded or patterned, distal end or feet101 of plunger 91 as is shown in FIGS. 9 through 12. Plunger 91 is aunitary and generally cylindrical member having a threaded proximal end103, a waist segment 105 and a pair of bifurcated and spaced apart legs107 separated by a longitudinally elongated slot 109. It has acollet-like configuration. Furthermore, a pair of laterally enlargedabutment ankles 111 serve to abut against and push pierce nut 33 wheninstalled thereon. Externally threaded or patterned feet 101 extend fromankles 111 and have peaks and valleys thereon with a lead-in taper ofabout 60° from one side to the other. The peaks are generally rounded toallow the feet 101 to be longitudinally and linearly pushed into piercenut 33 by lateral flexing of legs 107 toward each other so that thepeaks temporarily but firmly engage within the internal threads ofpierce nut 33. The periphery 51 of pierce nut is also held withinbifurcated leading end of punch assembly 85 as can best be viewed inFIGS. 1, 4, and 5. This prevents rotation of the nut during workpieceinsertion.

Frangible wires 55 securing the leading pierce nut 33 to the remainderof the pierce nut string are severed when piston 93 thereafter retractsbody 57 toward base 41 and the leading pierce nut 33 is correspondinglywithdrawn adjacent a wire cutting edge 121 of guide block 121. Theleading pierce nut is then ready for insertion into the workpiece aswill be later discussed. Therefore, it should be apparent from the abovediscussion as to the present advantageous construction and ability tofeed and retain the pierce nuts onto the punch assembly without thecomplexity of internal components as used in traditional machines.

It also noteworthy that an internally protected channel is provided fora wire 123 as is shown in FIGS. 6-8. One end of this wire is connectedto a sensor 125 (see FIGS. 2 and 3) which is fastened to an outside ofpunch 85 immediately adjacent its distal end which senses if a nut isretained by plunger 91 after the nut is severed from the nut string.Wire 123 fits within an internal passage of punch 85 and also within anupper channel 127 of base 41. An opposite end of wire 123 is connectedto a control panel/PLC. Additionally, a nut present sensor 131 (see FIG.8) is attached to nose plate 122 for sensing if the leading pierce nut33 has advanced into a position aligned with axis 199 prior toengagement with plunger 91. A wire 133 extends from sensor 131 to thecontrol panel/PLC. Additionally, proximity sensors 137, used to sensethe stroke or travel positioning of feeder piston 141 (see FIG. 3) areconnected to a switch pack and connector 135.

An alternate die is shown in FIGS. 1, 7 and 13-18. Die 39 includes astationary body 201 having a substantially cylindrical peripheralsurface and generally flat top and bottom surfaces (as viewed in theFigures). Primary and secondary clinching formations 203 and 205,respectively, project in a generally rectangular shape from the topsurface of die body 201 in the present embodiment. The clinchingformations each have tapered side walls 207 and a flat edge or surface209 at its top when viewed in cross-section; alternately, the edge has abevel oriented to form a higher cutting line adjacent an interior ofedge 209. Inner walls 211 downwardly extend from the cutting lines ofedge 209 and are in communication with an enlarged interior bore 213having a generally cylindrical shape. Secondary formation 205 issimilarly constructed.

Furthermore, compression springs 221 are secured within correspondingcylindrical passageways 223 in die body 201. A lower end of eachcompression spring is secured by a laterally elongated roll pin 225 andan upper end of compression spring 221 longitudinally biases an enlargedhead of an ejection or stripping pin 227, an end of which operablyprojects through a corresponding hole in the top surface of die body201. This upwardly pushes the workpiece away from the die after the nutis attached to the workpiece.

During pierce nut insertion, workpiece 35 is placed upon edge 209 of die39 while the press is in an open position, and generally simultaneouswith feeding and loading of the piece nut onto the plunger. Thereafter,the upper platten or press shoe 43 is lowered which causes plunger 91 toadvance the leading pierce nut 33 on top of workpiece 35, aligned withlongitudinal axis 199. The lower surface of pierce nut will act inconjunction with edge 209 of die 39 to first pierce and sever agenerally rectangularly shaped blank 251, corresponding to theintersection of edge 209 and inner walls 211. Blank 251 exits die 39through bore 213 and an attached tube. Next, the remaining interior edge253 (see FIG. 12) of workpiece 35 is then upwardly bent by the side wall207 so as to be clinched and secured into corresponding grooves in alower surface of pierce nut 33. These bottom grooves in nut 33 may beundercut or the like. Thereafter, reopening of the press will cause thefeet of the plunger to linearly pull out of the nut so the workpiece canbe transferred out of the tool.

The piercing and clinching of the workpiece to the nut only occurs forthe primary formation 203 of die 37 and not for the supplementalformation 205 in the preferred construction. Supplemental formation 205is provided as a replacement piercing and clinching formation after wearhas occurred to the primary formation. After which, the die is unscrewedfrom the corresponding platten or shoe 45 of the press, reversed, andthen reattached thereto. This secondary formation provides for a verysimple, inexpensive and convenient replacement in a single piece andintegrated manner.

FIG. 19 shows a second alternate embodiment piercing and clinchingformations 261 for die 39. Two or more sections of a formation edge 263are each provided with a centralized and localized peak 265. Thisincreases point-loading against the lower surface of the workpieceduring the piercing. It is envisioned that this will advantageouslydecrease the press forces required to pierce the pierce nut into theworkpiece. The edge may also be beveled in cross-section with thehighest elevation being closest to the internal walls defining the blankreceiving hole. The primary and secondary formations show differentconfigurations of the locally peaked feature. Finally, FIG. 20 shows yetanother alternate embodiment of die 39 wherein only a single piercingand clinching formation 267 is employed.

Base 41 and body 57 are preferably machined from hard coated aluminum tominimize weight. Plunger 91 and punch 85 are preferably machined from4140 hot rolled steel and 6150 hot rolled steel rods, respectively; theplunger is then hardened and ground to about Rc 40-44. Moreover, diebody 201 is preferably machined from an M2 steel rod.

A preferred embodiment of the present pierce nut insertion tool 301 isshown in FIGS. 21-29. A base 303 is screwed to a mounting block 305 (seeFIG. 21) which, in turn, is affixed to an upper platten 307 of avertically moveable press. A shoe or body 309 is movably coupled to base303 by way of a pneumatically driven piston including a piston head 311and a piston rod 313. Piston head 311 is vertically movable within apiston chamber or cavity 315 located partially within base 303 andpartially within an extension cylinder 317 provided within an end cap319. Piston rod 313 further includes a vertically elongated and centralchannel or slot 321 which moves about a guide 323 affixed to base 303 toprevent rotation of the piston when linearly moving. A distal end ofpiston rod 313 is affixed to body 309 via screw 325.

A punch assembly 351, including a punch 353 and plunger 355, aregenerally the same as with the prior embodiment. It is alternatelyenvisioned, however, that a solid and rigid plunger that only abutsagainst an upper surface of a pierce nut 357 without entering a hole inthe nut, can be used although various advantages of the prior embodimentmay not be realized. Punch assembly 351 serves to linearly drive eachnut 357 from a leading feed position aligned with a punch axis to apiercing and clinching position against a workpiece 535. A conventionaldie with a single clinching formation can be used on an opposite side ofthe workpiece.

A detent mechanism 371 can best be observed in FIG. 29. Detent mechanism371 includes a detent member 373 having a middle post upon which islocated a laterally expanded ledge and an upper wedge surface 375 havinga tapered angle offset from a nut feeding direction. A compressionspring 376 or belleville washer serves to upwardly bias detent member373 away from a screw-in or snap-in cap 377 retaining mechanism 371 tobody 309. In operation, advanced feeding of the string of connected nuts357 toward punch assembly 351 causes tilted deflection and linearretraction of detent member 373 toward cap 377. When the central hole ofnut 357 overlies detent member 373, however, detent member 373 willfully advance such that a leading surface 379 thereof will abut againstan inner edge defining the nut hole to deter undesired rearward andretracted movement of the nut string. This action serves to temporarilyhold the nuts when a pawl ratchets back to a subsequent nut as will befurther discussed hereinafter. A release finger 381 downwardly extendsthrough an aperture in cap 377 to allow manual tilting and disengagementof detent member 373 if manual retraction of the nut string is desired.

Referring now to FIGS. 21-26 and 29, an internally valved andcontrolled, pneumatic fluid actuation system is shown for feeding theconnected string of nuts 357. A hollow elbow fitting 401 is attached tothe upper surface of body 309 in a threaded manner in alignment with aninternal fluid passageway 403. A distal end of fitting 401 mates with anair supply hose. When the insertion tool is closed, as illustrated inFIGS. 21 and 29, air flowing through a first longitudinal and horizontalpassageway 405 will abut against and be blocked by a nominal cylindricaloutside surface 406 (see FIG. 22) of a vertically moveable shaft orspool 411. In this situation, an internally mounted valve 423 is in itsnormally closed and unactuated condition. Furthermore, a compressionspring 441 therefore pushes a front end of a nut feeding piston head 427to its retracted position. A compression spring 413 serves to downwardlybias spool 411, the upper section of which is hollow for receiving aportion of the spring.

FIGS. 23, 25 and 26 illustrate body 309 moved to an intermediateposition approximately 5.5 mm above the fully open position byadvancement of piston head 311 and rod 313. In this condition, anannular groove 409 of spool 411 provides open airflow access spanningaround a central O-ring seal 407 in body 309. This allows air to flowfrom passageway 405 to lateral passageway 421, and then to a secondlateral passageway 422. Accordingly, the air is transmitted to aninternal control valve 423 mounted within and moving with body 309.Valve 423 is preferably a cartridge insert, three way, air-pilot valvewhich can be obtained from Humphrey Products, Co. of Kalamazoo, Mich.The air-pilot valve uses the initial air pressure passing through groove409 of spool 411 to shift a gate of the valve to an open and actuatedcondition in a very fast manner with a relatively small amount of pilotair flow pressure. This allows the full inlet air pressure throughfitting 401 to be directed onto a rear face 425 of nut feeding pistonhead 427 via internal body passageways 422 and 424 (see FIG. 24). Thus,approximately 80 psi of air pressure enters a piston cavity 461,overcomes spring 441 and moves piston head 427 from the retractedposition, shown in FIGS. 21 and 29, to the advanced position shown inFIG. 24.

Opening of body 309 from the closed position of FIGS. 21 and 29, to thefully open position of FIG. 26, advances a nut feeder. The nut feederincludes a nut feeding piston rod 431 upon which is journaled a knuckle433, via a pivot pin 537. A compression spring 435 serves to downwardlybias knuckle 433 such that a removable, tapered pawl 437 advances thecorresponding nut within which it is engaged. This advancing motion ofpiston head 427 also compresses compression spring 441. The string ofnuts 357 is connected by a pair of elongated wires and initially fedinto an end of body 309 in a nut path or track located on an oppositeside of the nut feeder and nut feeding piston from base 303 and platen307. The nuts are fed in a linear direction generally parallel to anadvancing direction of piston head 427 and feeder. Additionally, amanually accessible knob 443 is connected to piston head 427 by way ofan intermediate structure 445 so as to allow manual overriding advancingand/or retraction of the nut feeding pawl 437 during initial loading orremoval of the nuts.

In the FIGS. 22 and 24 fully open orientation, an upper ledge 451 ofspool 411 abuts against a corresponding step 453 in a verticalcounter-bore 454. This serves to pull up the spool. Valve 423 isactuated until body 309 begins to close, wherein the air is exhausted.However, valve 423 is not closed at the fully retracted and closedposition. An exhaust outlet 463 and a muffler valve vent 465 areprovided to allow the escape of air.

It is noteworthy that the internally valved construction of the presentembodiment provides a considerably faster cycle time then with anexternally valved approach. Furthermore, no controller programming isrequired for nut feeding with the preferred embodiment arrangement whilethis embodiment additionally simplifies installation set-up of the nutfeeding mechanism in a fool-proof manner. Furthermore, proximity sensorsare not required to sense piston location for nut feeding thereby savingadditional expense, packaging space and maintenance concerns.

While various constructions of a pierce nut insertion tool have beendisclosed, alternate embodiments may be employed. For example, hydraulicfluid actuators or electromagnetic actuators can be used for moving thebody relative to the base and/or moving the feeder in some of theembodiments, however, various advantages of the present tool may not beachieved. Furthermore, the collet-like plunger may have three, four or agreater number of flexible legs, however, various advantages of thepresent tool may not be realized. Alternately, the die may include morethan two of the piercing and clinching formations. Moreover, different,additional or varying locations of fasteners, sensors, fluid passagewaysand connectors may be utilized, but this may forfeit certain advantagesof the present tool.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the disclosure. Individual elements or featuresof a particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.It is intended by the following claims to cover these and any otherdepartures from the disclosed embodiments which fall within the truespirit of this invention.

The invention claimed is:
 1. A method of using a pierce nut insertiontool comprising: (a) applying fluid pressure to advance a piston towarda punch axis; (b) feeding pierce nuts along a path, located on anopposite side of the piston from a moveable press platten, in responseto step (a); (c) moving the nut path and piston away from the platten byan actuator to assist in the pierce nut feeding; (d) allowing one of thenuts to be advanced and aligned with the punch axis; (e) moving the nutpath and piston toward the platten, after step (d); and (f) creating ahole in a workpiece and clinching the pierce nut to the workpiece by thepunch pushing the pierce nut against the workpiece.
 2. The method ofclaim 1, further comprising controlling advancing actuation of the nutfeeding piston with a fluid valve attached directly to and moveable witha body containing the nut path, the body being moveable relative to theplatten.
 3. The method of claim 1, further comprising moving the nutfeeding piston entirely inside a body moveable with the nut path, thebody being moveable relative to the platten, and a fluid passagewaylocated within the body being coupled to a piston cavity.
 4. The methodof claim 1, further comprising moving the nut feeding pistonmechanically independently of a base holding the nut setting punch. 5.The method of claim 1, further comprising controlling fluid flow to thenut feeding piston by selective alignment of a shaft spanning between abody holding the piston and a base holding the punch, the body beingmoveable relative to the base and the base always moving with theplatten.
 6. The method of claim 1, furthering comprising temporarilyholding together the pierce nuts in a linear string for simultaneousfeeding toward the punch axis, and severing the one of the pierce nutsto be inserted by the punch from the string of the pierce nuts.
 7. Themethod of claim 1, further comprising sensing if one of the pierce nutsis present in a position aligned with the punch axis with a sensorelectrically connected to a programmable controller and the programmablecontroller controlling the application of the fluid pressure.
 8. Amethod of using a pierce nut insertion tool comprising: (a) applyingfluid pressure to advance a piston in a first direction toward a punchaxis; (b) moving a pierce nut-feeder in the first direction in responseto step (a); (c) advancing a pierce nut-insertion punch in a seconddirection substantially perpendicular to the first direction; and (d)varying the timing of subsequent feeder movement relative to subsequentpunch advancing only through a programmable controller change.
 9. Themethod of claim 8, further comprising: moving a tool body away from atool base, the nut-feeding piston being at least partially locatedwithin the tool body and the punch being stationarily mounted to thetool base; and applying fluid pressure to move the tool body relative tothe tool base in at least one operating condition.
 10. The method ofclaim 9, further comprising advancing a piston which moves the tool bodyrelative to the tool base along a centerline piston axis which issubstantially perpendicular to the first direction, the centerlinepiston axis intersecting the first direction between a head of thenut-feeding piston and the punch axis in all operating conditions, andpneumatically powering all of the pistons.
 11. The method of claim 8,further comprising moving a press platten, to which the punch isstationarily mounted, in order to advance the punch toward a die mountedto an opposite press platten.
 12. The method of claim 11, furthercomprising piercing and securing an internally threaded pierce nut to ametallic panel located between the punch and the die.
 13. The method ofclaim 8, further comprising manually moving the pierce nut-feederthrough moving an extension arm projecting from an end of the piston.14. The method of claim 8, further comprising moving a fluid valve witha tool body that contains at least part of the feeder and piston.
 15. Amethod of using a pierce nut insertion tool comprising: (a) advancing astring of temporarily attached pierce nuts toward a punch axis by use ofa fluid powered pawl; (b) moving a tool body at least partiallycontaining the pawl and pierce nuts away from a tool base to which apunch is mounted to allow alignment of one of the pierce nuts with thepunch; (c) moving the tool body toward the tool base to sever the one ofthe pierce nuts from the string; and (d) using fluid actuation to movethe tool body relative to the tool base in at least one of steps (b) and(c).
 16. The method of claim 15, further comprising: moving a pressplatten, to which the punch is stationarily mounted, in order to advancethe punch inward toward a die mounted to an opposite press platten, eachof the pierce nuts including a substantially rectangular periphery andan internally threaded hole within which the pawl contacts; and rotatingthe pawl relative to a fluid powered piston.
 17. The method of claim 15,further comprising selectively supplying pneumatic pressure to a pistonentirely moveable with the tool body through a valve also entirelymoveable with the tool body.
 18. The method of claim 15, furthercomprising: moving a press platten to which is mounted the punch,relative to an opposite press platten to which is mounted a die; andpiercing and securing the one of the pierce nuts to a metallic panellocated between the punch and the die, the die including a cylindricalperipheral surface and more than one inner through-passageways.
 19. Themethod of claim 15, further comprising sensing if the one of the piercenuts is present in a position aligned with the punch axis using a sensorelectrically connected to a programmable controller, and theprogrammable controller controlling application of the fluid pressure.20. The method of claim 15, further comprising: advancing a first pistonparallel to a feeding direction of the string when the string is insidethe tool body, the first piston driving the pawl in at least oneoperating condition; and advancing a second piston parallel to the punchaxis to drive the tool body relative to the tool base in at least oneoperating condition.